• Journal of Environmental Health Sciences
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• v.19 no.4
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• pp.1-9
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• 1993

Since most people spend a large majority of their time indoors (at least in the industrialized countries), indoor air may affect human health more than outdoor air. This study was carried out to characterize the reference and equivalent methods against the low volume method which was promulgated by the Ministry of Health and Social Affairs. The Laser and Piezo air sampler offer the advantage of real time data and low labor costs. The arithmetic mean concentrations were found to be 102.9% (Laser-2 min method) and 65.9% (Piezo method) against low volume method (100%). The statistical analysis procedure for this comparision is linear regression. The linear regression line of low volume method had slopes of 0.5487 and 0.9697 and Y intercepts of 0.0266 and 0.0110 $\mu$g/m$^3$ about Laser (2 min) and (24 h) method respectively. And the correlation coefficients were 0.7271 and 0.9433.

• Proceedings of the IEEK Conference
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• 2001.06c
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• pp.33-36
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• 2001

With all the researches to define human genom and to look for some new bio-activated material in the bio-technology field recently, it is more highly needed to analyse DNA or so called Material than ever before. First, the lanes are extracted based on histogram analysis and projection technique. And then three other approaches are applied for band extraction: SB, RG-1, and RG-2. In SB method, a search line is set dividing each lane equally and vertically to find peaks and valleys. And according to them, minimum enclosing rectangle of each band is determined. In RC-1 approach, on the other hand, band areas are extracted by region growing with the peaks as seeds, avoiding the overlap with the neighboring bands. In RC-2 approach, peaks and valleys are searched in two lines that trisect the lane vertically, and the pair of peaks in the same band are determined, and then used to grow the region. To compare the accuracy of the three suggested methods, we measure the location and amount of bands. The result shows that the mean deviation of the location is 0.06, 0.03, and 0.01 for SB, RG-1, and RC-2 respectively. And the mean deviation of the amount of bands is 0.08, 0.05, and 0.02 for SB, RG-1, and RG-2 respectively. In conclusion, the RG-2 method suggested in this paper appears to be the most reliable on the degree of the accuracy in measuring the location and amount of bands

• Journal of the Korean Home Economics Association
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• v.38 no.12
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• pp.111-129
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• 2000

The purpose of this study is to investigate the level of consumer instantly impulse buying in cuber market user. Also this study analyzes causal effect on consumer instantly impulse purchasing by demographic and social, place and promotion, consumer emotion state, and consumer internal and psychological variables. The data had been collected from on-line research method with 1,034, as using cuber market. The major statistical methods used for data analysis are frequency, percentile, mean, factor analysis, multiple regression analysis, Pearson's correlation analysis, and path analysis. The result of causal effect analysis were as follows; First, the variables affecting possession oriented materialism were sex and age. Second, the variables affecting self-control were sex, income, account of credit card, and instantly state of mind. Third, variables directly affecting instantly impulse purchasing were serif employed, banner advertisement, experience of cuber shopping, shopping mall pattern, instantly state of mind, purpose of shopping, happiness and success oriented materialism, and self-control. Also sex, income account of credit card, and instantly state of mind emerge to indirectly effect via self-control. Especially, the variables of success oriented materialism and instantly state of mind influenced on the highest of relative variables in consumer instantly impulse purchasing.

• The KSFM Journal of Fluid Machinery
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• v.11 no.2
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• pp.38-45
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• 2008

This study presents a numerical procedure to optimize the compressor design to increase the surge margin of compressor with response surface method (RSM). The Box-Behnken design method is used to reduce the number of calculation for fitting the second-order response surface. In order to consider the increase of surge margin during numerical optimization without any calculation at the surge point, the slope of compressor characteristic curve at the design point is suggested as an objective function in the present optimization problem. Mean line performance analysis method is used to get the design and off-design characteristic curves of centrifugal compressor. The impeller exit angle, impeller exit height and impeller radius are chosen as design variables. The optimum shapes show the increase of surge margin for the surge margin optimization and increase of efficiency for the efficiency optimization in comparison with an initial shape.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.7 s.250
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• pp.603-611
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• 2006

This paper presents the response surface optimization method using three-dimensional Wavier-Stokes analysis to optimize the blade shape of an axial flow fan. Reynolds-averaged Wavier-Stokes equations with $k-{\epsilon}$ turbulence model are discretized with finite volume approximations using the unstructured grid. Regression analysis is used for generating response surface, and it is validated by ANOVA and t-statistics. Four geometric variables, i.e., sweep and lean angles at mean and tip respectively were employed to improve the efficiency. The computational results are compared with experimental data and the comparisons show generally good agreements. As a main result of the optimization, the total efficiency was successfully improved. Also, detailed effects of sweep and lean on the axial flow fan are discussed.

• Wind and Structures
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• v.7 no.6
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• pp.359-372
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• 2004

Wind tunnel model studies were carried out to determine the wind load distribution on tributary areas near the gable-end of large, low-rise buildings with high pitch planar and curved roof shapes. Background pressure fluctuations on each tributary area are described by a series of uncorrelated modes given by the eigenvectors of the force covariance matrix. Analysis of eigenvalues shows that the dominant first mode contributes around 40% to the fluctuating pressures, and the eigenvector mode-shape generally follows the mean pressure distribution. The first mode contributes significantly to the fluctuating load effect, when its influence line is similar to the mode-shape. For such cases, the effective static pressure distribution closely follows the mean pressure distribution on the tributary area, and the quasi-static method would provide a good estimate of peak load effects.

• Journal of Biomedical Engineering Research
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• v.26 no.2
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• pp.87-93
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• 2005

A new method for real-time estimating left ventricular relaxation time constant (T) from the left ventricular (LV) pressure waveform, based on the isovolumic relaxation model, is proposed. The presented method uses a recursive least squares (RLS) algorithm to accomplish real-time estimation. A new criterion to detect the end-point of the isovolumic relaxation period (IRP) for the estimation of T is also introduced, which is based on the pattern analysis of mean square errors between the original and reconstructed pressure waveforms. We have verified the performance of the new method in over 4,600 beats obtained from 70 patients. The results demonstrate that the proposed method provides more stable and reliable estimation of τ than the conventional 'off-line' methods.

• The Transactions of the Korea Information Processing Society
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• v.6 no.9
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• pp.2470-2478
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• 1999

In this paper, algorithm is proposed to forecast line utilization using SNMP MIB-II. We calculate line utilization using SNMP MIB-II on TCP/IP based Internet and suggest a method for forecasting a line utilization on the basis of past line utilization. We use a MA model taking difference transform among ARIMA methods. A system for orecasting is proposed. To show availability of this algorithm, some results are shown and analyzed about routers on real environments. We get a future line utilization using this algorithm and compare it ot real data. Correct results are obtained in case of being few data deviating from mean value. This algorithm for forecasting line utilization can give effect to line c-apacity plan for a manager by forecasting the future status of TCP/IP network. This will also help a network management of decision making of performance upgrade.

• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.567-571
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• 2011

Air Starter motors are used for the start of medium-speed diesel engine. One of the main part of air starting motors is the axial turbine stage. In this study, design of 1-stage axial type turbine for 14kw class air starter motors has been performed. The turbine blade was designed based on mean-line analysis. 1-D design calculation and numerical analysis with CFD were conducted iteratively. The validation between 1-D design method and numerical analysis for axial clearance has been performed. It revealed that there is optimum axial clearance of turbine design.

• Korean Institute of Interior Design Journal
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• v.20 no.1
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• pp.165-172
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• 2011

Visitors' behaviors within an exhibition space are a substantial means to grant spatial arrangement and validity of exhibits. Therefore, the study analyzed visitors' behaviors in the viewpoint of attraction power and holding power of exhibits on the basis of exhibition layout of real science museums. Through the analysis, the study grasped efficiency of analysis index and exhibition environment elements which might have an effect on planning the exhibition space of a large-scale museum and producing detailed ranges of exhibition. The main indicators used are: 1. Attraction power: it indicates the relative incidence of people who have stopped in front of an object/exhibit during the exhibition tour. It is calculated by dividing the number of people who stop by the total number of people who have visited the museum or gallery. 2. Holding power: it measures the average time spent in front of an information/communication element. It is calculated by dividing the average time of stay by the time "necessary" to read an element. As a result, It was expected that attraction power and holding power of exhibit would be increased when moving line of seeing was inductive. However, when the traffic movements of seeing was inductive, repetitive seeing of exhibit was almost never realized and visitors had a strong tendency which viewed on their way of moving without viewing on their way of stopping. On the other hand, it may mean that density of exhibit is low or size of exhibition space is small that most of exhibits within exhibition space have high attraction power and holding power. As Gwacheon National Science Museum, when a museum is composed of many large-scale exhibit halls, it should be formed by separating the main moving line of seeing from the optional moving line of seeing through visitors' natural choice of exhibit and proper inducement of moving line of seeing. In such structure, exhibition environment of the main moving line has an effect on attraction of exhibit and the use of optional moving line acts as a factor to increase attraction. In addition, it is thought that attribute of exhibit and proper arrangement of rest space within exhibition space will increase holding power of exhibit.